Results 81 to 90 of about 3,792,347 (201)

On maximal immediate extensions of valued division algebras [PDF]

, 2003
We show an extension theorem for strictly contracting bilinear mappings into a spherically complete valued vector space and we apply this result to prove that every maximal valued division algebra having the same characteristic as its residue division ...
Schörner, Erwin
core   +1 more source

Non-local non-linear sigma models

Journal of High Energy Physics, 2019
We study non-local non-linear sigma models in arbitrary dimension, focusing on the scale invariant limit in which the scalar fields naturally have scaling dimension zero, so that the free propagator is logarithmic.
Steven S. Gubser, Christian B. Jepsen, Ziming Ji, Brian Trundy, Amos Yarom   +4 more
doaj   +1 more source

Max–min measures on ultrametric spaces

Topology and its Applications, 2013
The ultrametrization of the set of all probability measures of compact support on the ultrametric spaces was first defined by Hartog and de Vink. In this paper we consider a similar construction for the so called max-min measures on the ultrametric spaces. In particular, we prove that the functors max-min measures and idempotent measures are isomorphic.
Cencelj, Matija, Repovš, Dušan, Zarichnyi, Michael   +2 more
openaire   +2 more sources

Concentrated vulnerabilities in bees: Diet specialists have smaller geographic ranges

Insect Conservation and Diversity, Volume 19, Issue 5, Page 1114-1123, September 2026.
Niche breadth theory predicts a positive association between range size and diet breadth, which could concentrate risk among specialists, but this is not well established for bees. Using global occurrence data (range size) and natural history collection‐derived pollen data (diet breadth), we compared these traits in 633 species from six families and ...
Charles N. Thrift, Thomas J. Wood, An Bui, Hillary S. Young, Katja C. Seltmann   +4 more
wiley   +1 more source

Isometries of ultrametric normed spaces

, 2021
We show that the group of isometries of an ultrametric normed space can be seen as a kind of a fractal. Then, we apply this description to study ultrametric counterparts of some classical problems in Archimedean analysis, such as the so called Problème ...
Navarro Garmendia, José, Cabello Sánchez, Javier   +1 more
core   +1 more source

Weak Monotone Fixed Points for Positive–Negative Guarded Language Systems in a Length-Based Ultrametric Space

Axioms
We study positive–negative guarded systems of language equations over a fixed finite alphabet. The ambient space is the complete ultrametric space of all formal languages equipped with a length-based distance, where two languages are close whenever they ...
Laura Ajeti, Hristo Hristov, Atanas Ilchev, Boyan Zlatanov   +3 more
doaj   +1 more source

Cryptic diversity and recent diversification in the Pyrrhulina australis species complex (Characiformes, Lebiasinidae) revealed by mitochondrial DNA

Journal of Fish Biology, Volume 109, Issue 3, Page 1771-1785, September 2026.
Abstract Pyrrhulina australis Eigenmann & Kennedy, 1903, is widely distributed across the main hydrographic basins of South America. The taxonomic integrity of this species is nevertheless challenged by the lack of clear diagnostic characters, its marked geographic variation and the morphological overlap with its congeners. In this context, the present
Taina Barbosa De Souza, Daniela Cristina Ferreira, Hugmar Pains Da Silva, Carolina B. Machado, Claudio Oliveira, André L. Netto‐Ferreira, Paulo C. Venere   +6 more
wiley   +1 more source

Ultrametricity and energy landscape in photonic spin glasses

Physical Review Research
Hierarchy is the architecture of complex systems. While Euclidean metric describes homogeneous and static systems, ultrametric geometry is for heterogeneous ensembles, hierarchic relations, and dynamic contexts.
Josivanir G. Camara, Davinson Mariano Da Silva, Stefano Ferretti, Silvia Gentilini, Claudio Conti, Neda Ghofraniha   +5 more
doaj   +1 more source

Metric spaces with small rough angles and the rectifiability of rough self‐contracted curves

Journal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract The small rough angle (SRA$\operatorname{SRA}$) condition, introduced by Zolotov in arXiv:1804.00234, captures the idea that all angles formed by triples of points in a metric space are small. In the first part of the paper, we develop the theory of metric spaces (X,d)$(X,d)$ satisfying the SRA(α)$\operatorname{SRA}(\alpha)$ condition for some
Estibalitz Durand Cartagena, Jeremy T. Tyson   +1 more
wiley   +1 more source

Guarded Language Operators as Contractions in a Length-Based Ultrametric Space

Mathematics
We study a class of wrapping operators acting on the space of formal languages over a fixed finite alphabet. The underlying space is equipped with a length-based ultrametric, in which two languages are close whenever they coincide on all sufficiently ...
Hristo Hristov, Atanas Ilchev, Hristina Kulina, Boyan Zlatanov   +3 more
doaj   +1 more source